<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8" />
		<title>while</title>
		<style type="text/css">
			#txt{
				width: 600px;
				text-align: center;
				margin: auto;
			}
		</style>
	</head>
	<body>
		<div id="txt"></div>
		<script type="text/javascript">
			for(i = 0; i < 10; i++){
				for(j = 0; j < i; j++){
					document.getElementById("txt").innerHTML += "☆";
				}
				document.getElementById("txt").innerHTML += "<br/>"
			}
		</script>
	</body>
</html>
